:root {
    --line-border-fill:#3498db;
    --line-border-empty:#e0e0e0;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}
.container {
    text-align: center;
}
.progressLine {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    width: 350px;
    position: relative;
}
.progressLine::before {
    content: "";
    height: 4px;
    width: 100%;
    background-color:var(--line-border-empty);
    position: absolute;
    z-index: -1;
    
}
.progressLine .line {
    height: 4px;
    width: 0%;
    background-color: var(--line-border-fill);
    position: absolute;
    z-index: -1;
    transition:all 0.3s ease-in
}
.progressLine .circle {
    background-color: #fff;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    border: 3px solid var(--line-border-empty);
    display: flex;
    justify-content: center;
    align-items: center;
    color: #e0e0e0;
    transition:all 0.3s ease-out 0.3s
}
.progressLine .circle.active {
    border-color: var(--line-border-fill);
    color: #3498db;
}
.btn {
    margin: 40px 20px;
    padding: 10px 30px;
    background-color: var(--line-border-fill);
    border: 0;
    border-radius: 5px;
    outline: none;
    cursor: pointer;
    color: #fff;
    font-size: 14px;
}
.btn:active {
    transform:scale(0.98);
}
.btn:disabled {
    cursor: not-allowed;
}